In the field of electronic devices, the availability of high end display devices has become an industry standard. As a result, the complex data management and signaling schemes for state-of-the-art video systems has increased the demand for faster and more reliable data transport. Electric cables using metal conductors such as copper are used to pass data between transmitter (Tx) and receiver (Rx) components. However, at the required data rates, an exposed metal conductor acts as an antenna capable of propagating electromagnetic energy at frequencies that interfere with co-operating wireless circuits within the device. For example, cable interconnects have the capability of emitting (incidental) electromagnetic energy at frequencies that interfere with nearby wireless RF circuits (such as WiFi or Bluetooth). This interference can be particularly troublesome in small form factor computing devices such as a laptop computer. For example, incidental energy generated by metal conductors can couple with a nearby WiFi antenna resulting in reduced WiFi performance. In order to prevent such affects, expensive shielding or re-location of the sensitive circuits, or both, can be used to isolate the sensitive circuits from the incidental energy. Moreover, in addition to acting as an antenna, metal conductors experience metal fatigue induced by repeated bending (during opening and closing of a lid of a laptop, for example). The metal fatigue results in damage to metal conductors (such as breaking) with the resultant loss of device functionality and reduced reliability.
One approach that is used to avoid the problems associated with using an unshielded or only partially shielded metal conductor for high speed data transport in small form factor electronic devices, and more particularly laptop computers, relies upon optical wave guides, and more particularly, fiber optic cables. Although, fiber optic cables eliminate the problems of incidental electromagnetic energy and metal fatigue, a photonic communication system that relies upon fiber optics generally requires a much more complex and expensive suite of circuits. For example, in order to generate optical signals, extra circuitry for lasers are required at a transmitter (Tx) portion of a fiber optic cable. Likewise, a photo-detector circuit (and amplifier) is required in a receiver (Rx) portion of the fiber optic cable. Moreover, power consumption used to operate the photonic communication system can be substantial. In portable systems that rely upon a battery for operating power, the increase power consumption reduces battery life. In addition to increased power consumption, manufacturing can be adversely affected since photonic based circuitry is not easily made compatible with the silicon-based integrated circuits (ICs). Furthermore, in order to minimize transmission loss, alignment precision of a few tens or hundreds of microns is required between electronic components and any fiber optic cable. Precision of this magnitude can substantially increase manufacturing complexity and reduce resultant yield loss with a concomitant increase in overall manufacturing cost.
A reliable and cost effective high speed data transport system for use in a portable computer is desired.